Incandescent electric lamp



UNITED STATES PATENT OFFICE.

\VILLIAM EMERY NICKERSON, OF CAMBRIDGE, MASSACHUSETTS.

INC AN DESCENT ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 503,669, dated August 22, 1893.

Application filed April 7, 1893. Serial No. 469,404. (No model.)

To all whom it may concern.-

Be it known that I, WILLIAM EMERY N IOK- ERSON, of Cambridge, in the county of Middlesex and State of Massachusetts, have invented a new and useful Improvement in Incandescent Electric Lamps, of which the following, taken in connection with the accompanying drawings, is a specification.

My invention relates to that class of incandescent electric lamps in which the glass globe is not continuous, butin whicha fusible cement, either in connection with a glass stopper or as a plug by itself, is used for the purpose of sealing or closing the neck of the lamp air tight.

It consists in a device by which the heat of the filament is prevented from reaching the neck of the lamp and softening the cement.

The accompanying drawings illustrate the application of myinvention.

Figure 1, shows in section an incandescent electric lamp embodying my device. Fig. 2, shows my device in connection with a supporting disk. Fig. 3, shows a method of duplication. Figs. 4, 5 and 6, show steps in the manufacture of my device.

In the drawings A represents the glass globe of an incandescent electric lamp, and B the filament attached at b b to the leading-in wires 0 C.

D is a disk of mica or other suitable substance adapted to support the plug of fusible cementE by which the lamp globe is rendered air tight. The plug of cementEis protected, from the radiant heat of the filament, (see Fig. 1,) by the hollow cone G, made of mica or other suitable substance. Owing to the reflection of the curved surfaces of the interior of the globe the heat of the filament tends to be largely concentrated into the neck of the lamp, and upon the cement plug E, unless the plug be protected. The cone G is located in the neck of the lamp with its apex toward the filament and its base to the disk D. The base of the cone is of such a diameter as to fit the neck of the lamp and be the'rebymaintained in position. The leading-in wires 0 0 pass through small holesin the sides of the cone and also tend to hold it in place. The angle of the cone is such that the heat rays from the filament and the interior surface of the globe strike its sides at an inclination at which they are nearly all reflected outward instead of passing through and striking the disk D. When the cement plug E is unprotected and the heat rays are allowed to strike it they are liable to heat and soften it.

In Fig. 2, a supplementary disk F is shown located in the neck of the lamp at the apex of the cone. This disk serves as a firm support for the cone.

Fig. 3, shows a method by which a second cone G may be used.

Fig. 4, shows the shape in which the sheet of mica or other substance may be cut, previous to forming it into a cone.

Fig. 5, shows the sheet formed into a cone and held in shape by small rivets I I. Instead of using the rivets I I the cone may be held together by having a small quantity of borax or boracic acid fused into the seam. H H are two small holes located in the sides of the cone, (see Fig. 5,) through which the leading-in wires pass. The wires may be inserted into the holes H H by means of cuts H H extending from the holes H H to the edge of the cone.

Fig. 6, shows the cone in plan with the base uppermost.

The gist of my invention consists in the use in an incandescent electric lamp of a cone of mica or other suitable substance located, in the neck of the lamp, for the purpose of reflecting the radiant heat of the filament outward in order to prevent the softening of a fusible cement by which the neck of the lamp is rendered air tight.

My device is equally applicable to lampsin which the neck is closed by a glass stopper rendered air tight by any'viscous'substance or cement.

'1 claim- 1. In an incandescent electric lamp, the combination of the glass globe A, filament B, leading-inwires O G, fusible cement plug E and cement-supporting disk D, said disk being located between the cement plug and the vacuous portion of the lamp and forming a part of the inclosingwalls of the vacuum chamber and adapted to prevent the cement from running into the lamp wh'en soft; with a coned reflector G, located within the neck of the lamp with its apex towardthe filament, adapted to protect the cement supporting disk D f rom the heatrays of the filament sjii'bstantially' as and for the purpose set forth,

2. In an incandescent electric lamp, the combination of the glass globe A, filament B and cement plngE; with asupplemental disk F, having a chamber between it and the cementplug'E and a refleetingcone G, s'r'ibstam tially as and for the purpose set forth.

3. In combination with an incandescent electric lamp; a heat reflector made inthe form of acone,with its apex centrally located I between theleading-inwiresand havingholesg in its conical surface for the passage of the leading-in wires, substantially as and for the 5 purpose set forth.

e e a,

FEAN'K G. PARKER,

FRANK G. HATTIE. 

